pNFS is a way to build massivly scaling NFS cluster by distributing the files over several servers. It will be standardized in NFS V4.1 and it will part of future Solaris. But when you already want to try it, you should look here. You find some tarballs there to bf-upgrade your Solaris installation for your own experiments. PS: You will find a good overview of pNFS at StorageMojo.